Multilevel security or multiple levels of security (MLS) is the application of a computer system to process information with different security levels, permit access by hosts with different security clearances and needs-to-know, and prevent hosts from obtaining access to information for which they lack authorization.
MLS systems often implement mandatory access control (MAC) to manage access to information within the system. Mandatory access control refers to a type of access control by which the system constrains the ability of a subject or initiator to access or generally perform some sort of operation on an object or target. Whenever a subject attempts to access an object, an authorization rule enforced by the system examines these security attributes and decides whether the access can take place. Any operation by any subject on any object will be tested against the set of authorization rules (or policy) to determine if the operation is allowed.
Although a number of suitable systems and methods have been developed to implement a MLS solution, it is generally desirable to develop improved systems and methods.